Article made of fibrous material and method of producing same



Patented Oct. 30, 1 928;

. UNITED STATES PATENT OFFICE.

WILLIAM HOFFMAN KOBBE, OF NEW YORK, N. Y., ASSIGNOR TO TEXAS GULF SULPHUR COMPANY, OF BAY CITY, TEXAS) A CORPORATION OF TEXAS.

ARTICLE MADE OF FIBROUS MATERIAL AND METHOD OF PRODUCING SAME.

No Drawing.

This invention relates to articles made of fibrous material, and has for its object the provision of an improved method of manufacturing such articles, as well as a new article of manufacture'made up of fibrous material and containinggypsum and sulfur.

The method of the invention involves building up the desired article of fibrous material, more particularly fabric, soaked or saturated with a thin slip or paste of gypsum plaster. The article is allowed to stand until the gypsum plaster has set, and will then possess sufficient rigidity for the next step. The fibrous article, made rigid by the set gypsum, is now impregnated with sulfur, preferably by immersion in a bath of molten sulfur. When the sulfur impregnation has proceeded to the desired degree, the article is withdrawn from the bath of molten sulfur, and the sulfur in the pores of the article is permitted to congeal in situ.

In practicing the invention I prefer to use fabrics such as cotton flannel, felt, jute, and the like. The fabric may be conveniently soaked or saturated with the gypsum plaster by drawing it through a thin slip or paste of'the plaster. The fabric, thus wet with the plaster, is then formed into the desired shape ofthe finished article. iently be done on an appropriate form or i collapsible or not as necessary. The saturated fabric remain 5' on the form un vi e plaster has set or hardened. The fabric serves as a convenient medium for holding the wet plaster, during the shaping of the article, while the plaster in setting imparts a desirable initial rigidity to the article.

It is ad'vantageousto thoroughly. dry the fabric-plaster article, or to at least remove a preponderance of the moisture therefrom, before impregnating with sulfur. This drying may be carried out in any appropriate manner, but I have found it preferable to di lowly at a temperature equal to or iter than the temperature of the impregna iig sulfur bath to be subsequently used so that a preponderance of the water of crystallization as well as the absorbed water will be driven off. If merely the absorbed water is driven off, the article, when subsequently placed in the molten sulfur, will only be superficially impregnated, as a thorough imp regnation of uncalcined gypsum articles This may conven Application filed March 14, 1927. Serial No. 175,430.

with sulfur cannot be obtained by merely immersing the article in the molten sulfur.

The impregnation of the dried fabric-plaster article with sulfur may conveniently be carried out in an open tank. The temperature of the sulfur bath may be 130 to 160 C.

If desired the impregnation with sulfur may be conducted in a closed tank with vacuum or pressure, or both. In withdrawing the article from the bath of. molten sulfur, care should be taken to retain the sulfur filling the pores or insterstices of the article until this sulfur has congealed in situ.

The resulting sulfur-impregnated fibrous plaster article is very strong, waterproof, and resistant to the action of, many corrosive liquors. The presence of gypsum in the fab-- ric minimizes the quantity of sulfur necessary for the requisite strength and thus reduces fire hazard and permits of the preforniing of ,fabric before the application of the sulfur saturating or indurating process. Where the invention isapplied. to the manufacture of ornamental and similar articles, various colors may be given the finished articles by dissolying sulfur-soluble dyes in the molten bath of impregnating sulfur, or by the other procedures described in my pending patent ap-.

plication Serial No. 61,831.

Cylindrical objects lend themselves particularly well to the practice of the invention.

Such objects as pipes, conduits, tubes and the like may be turned or wound on a cylindrical mandrel and the plaster saturated fabric material may. thus be very easily applied. When set, the fibrous-plaster article may be readily removed from the mandrel and dried. The dried --fibrous plaster article may then be treated in the sulfur impregnating bath.

The improved method of the invention permits the tempo ary forming of fabric and similar materials into various shapes which the gypsum plaster holds temporarily until the sulfur is injected therein. Tiler example,

in building up a pipe or conduit, strips of fabric may be passed through a thin slip of gypsum and wound on a mandrel, either spirally or straight and as soon as the plaster hasset, the forii'ied pipe, conduit or other object may be removed therefrom and after drying immersed in a bath of sulfur.

The invention dispenses entirely with forms for holding the fabric or fibrous mate- "a pm @1011 mug A m d m as]; 50 i (3011011311:

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